Impeller for heavy duty comminuting pumps

ABSTRACT

An impeller for heavy duty comminuting pumps may include a blade which is not only disposed in angular relation to its turning axis but may have an irregularly curved surface, or several such surfaces arranged to intersect each other along a line which is angularly disposed with respect to the turning axis.

1 1 1111mm mics Pmem 1151 3,640,474

Niedl Feb. 0, 1972 [54] IMPIELLER FOR HEAVY DUTY COMMHNUTING PUMPS 1Reference Cited [72] Inventor: Georg Niedl, 1m Bisch 664, Schoan, UNITEDSTATES PATENTS Ledtensten 2,956,503 10/1960 Neidl ..103/111 x [22]Filed: Feb. 18, 1969 3,113,734 12/1963 Neidl ..24l/74 [21] APPLNO 822342Primary ExaminerD0nald G. Kelly Related US. Application Data Anameychnsten & sabol [62] Division of Ser. No. 452,502, May 3, 1965, Pat. No.ABSTRACT An impeller for heavy duty comminuting pumps may include ablade which is not only disposed in angular relation to its turn- 52]us. c1 ..241/46.02, 103/111,210/174, ing axis but may have anirregularly curved Surface or 241/4606 241/ 415/121 such surfacesarranged to intersect each other along a line 51 1111. C1 ..B02C 18/06,F04d 29/04, B0111 35/26 which is angulafly disposed with respect to memming am [58] Field 01 Search ..24l/46, 46.02, 46.06, 46.11,

241/90, 74; 103/111.1, 11l;415/121, 210/174 7 ClaimgQDr-awingligures L II Mum I54 5 I50 I 7 g j I5 A f M 140 PATENTEQFEB 8 I972 SHEEY 1 0F 2FIG. 2

FIG.

FIG. 4

FIG. 3

INVENTOR GEORGE NE IDL IMPELLER FOR IIIEAVY DUTY COMMINUTING PUMPS Thisapplication is a division of our copending application, Ser. No.452,502, filed May 3,1965, for a PUMP.

This invention relates to rotary pumps of the type disclosed in my priorUS. Pat. Nos. 2,956,503; 3,005,597; 3,060,862; 3,067,960; 3,113,734 and3,120,353 and more particularly to the development of said type ofmachines for separating solids and liquids.

In all known filter construction whether they used centrifugal force,screens, vacuum, pressure, filter cloth, filter drums, or other means,the filtering machine was construed as a separate single purpose unit.Said constructions presented, in addition, always the difficulty thatthe filter openings readily clogged and had to be cleaned in relativelyshort time intervals by scrapers or other means.

It is a principal object of the invention to provide a machine whichavoids said drawbacks.

A further object of the invention is to provide a machine which allowsof combining processing operations such as mixing, tearing, comminuting,grinding, homogenizing, centrifuging, milling, kneading as well asseparating, sorting, distilling with a filtering and pumping action.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein preferred embodiments of the invention are shown byway of example.

In the drawings:

FIG. I is a view of a disc-shaped rotor;

FIG. 2 is a view ofthe rotor of FIG. 11 in its folded form;

FIG. 3 is a sectional view of such rotor;

FIG. 4 is a perspective view of the rotor inside the pump housing;

FIG. 5 is a view of the same rotor provided with teeth;

FIG. 6 is a longitudinal section, partly in elevation, of a pump withthe rotor of FIGS. 11 to 15, cooperating with grooves in the pumphousing, and

FIGS. 7, 8, and 9 show various schematic forms of folded pump discs.

FIGS. I to 9 illustrate various fonns and shapes of the impeller discs.FIG. 2 shows the rotor disc 139 of FIG. I, mounted on shaft 140, foldedabout its center axis 141, as better seen from the section I-I, wherethe folding angle has been designated a. The inclined mounting of thefolded impeller disc I39 is shown in FIG. 4, where it is rotated in ahousing I44 having an inlet I45 and an outlet I46.

FIGS. 5 and 6 show an embodiment of the invention where the foldedimpeller disc I47 is, similar to the modification shown in FIG. 9 of thedisclosure of US. Pat. No. 3,502,274, provided with teeth I54 and I55running in radial grooves 148 of a housing I49 and in concentric grooves150 and 151 of covers 152 and I53, respectively. The parts 149, I52, andI53 are perforated by passages 157 through which the filtrate iswithdrawn.

Such folded toothed rotor may be disposed in a simple spiral housingrotating with its teeth in radial grooves, whereby the spiral housing isprovided with a suitable outlet. Instead of being flat, one or both ofthe two wings of the folded impeller may be arched to form a scoop.

The folded rotor of FIG. 7 is no longer flat as in FIG. 3 but a foldedsemicircle 161. The one flank 162 of the quarter circle is left in itsplane, the second flank 163 is turned over by 90 to position I64. Thethus formed rotor is secured obliquely to the shaft 165 which extendsperpendicularly to the plane of the drawings.

FIG. 8 shows the half circle I66, 167 with its flank 167 turned towards168. In FIG. 9, the part 171 of the generatrix I70, I71 is tilted by 90to position 172, producing the rotor I70, 172. Such rotors, which mightbetter be designated operating members, may replace the rotor I of FIG.I of the disclosure of U.S. Pat. No. 3,502,274; instead of using therotor 170, 172 of FIG. 9, a double-arched body 170, 171 may be employed.According to may investigations, it is of advantage in many cases that170 and I71 be shaped to form a drag curve Schlep kurve see Rothe,Hohere Mathematic, page I40, erlag or Wrssenschaft und Fachbuch-GmbI-I.,

Bielefeld, 1949).

In the modifications of the rotor shown in FIGS. 1-9, it is notnecessary to tilt the half generatrix, such as I63, I67, 171 by Theangle may be larger or smaller, even negative. In the latter case, saidhalf generatrices are turned not counterclockwise but clockwise withrespect to the other half generatrices I62, I66, I70.

Neither is it necessary that in the rotors of FIGS. 8-9 the wings haveequal length, i.e., end on the same diameter circle. They may havedifferent lengths, or one wing may be completely omitted. On the otherhand, a rotor may have more than two wings.

The wings may be perforated, and they may have other types of curvaturesthan those shown. I

The use of folded rotors as shown in FIGS. 4-9 is particularly suitablefor the treatment of long or strong fibered or very tough material.Viewing, e.g., the machine of FIG. 5, it will be seen that a current ofslurry entering through inlet will be divided in half on hitting againstthe folded edge of rotor 147. This has two advantages: Shifting of thematerial inside the engine is less likely, and separation through thepassages 157 is faster and more intensive. The two rear edges of therotor sweep on rotation the apertures 157 with a short interval; thereis a rather wide angle before the next sweep of the two edges takesplace, and apertures have, therefore, more time to recover from thepassage'of the filtered material than in case of a rotor disc as shownin FIG. I of the disclosure of US. Pat. No. 3,502,274, where the angleis I80. Such periodical combing of the passages 157 can be furtherimproved by making the same of different sizes, as indicated e.g., inFIG. 9 of the disclosure ofU.S. Pat. No. 3,502,274.

I claim:

I. A pump and strainer assembly comprising a stationary pump housinghaving an inner wall defined by a surface of revolution forming a pumpchamber in said housing, one end of said chamber being provided with aninlet, a rotary drive shaft mounted in said chamber concentric with theaxis of said surface of revolution, an impeller secured to said driveshaft, a shell enclosing at least a part of said pump housing, saidshell forming with the wall of said enclosed pump housing a separateoutlet chamber, the portion of said housing enclosed by said shell beingprovided with a plurality of strainer passages, said impeller comprisinga plurality of semielliptical wings, said wings being generally disposedin planes angularly related to each other and angularly related withrespect to the axis of said surface of revolution.

2. An assembly as claimed in claim I wherein said impeller is folded toform two wings.

3. An assembly as claimed in claim 2 wherein said wings are formed bytwo planes meeting along a straight line.

4. An assembly as claimed in claim 2 wherein said wings are formed bytwo intersecting generally arcuately formed members.

5. An assembly as claimed in claim 2 wherein the folding edge of theimpeller is opposite the inlet of the pump chamber.

6. An assembly as claimed in claim 2 wherein said wings have differentlengths.

7. An assembly as claimed in claim I, wherein at least a portion of saidinner wall defining the pump chamber is provided with a series ofcircumferential grooves, and the margins of said semielliptical wingsare provided with teeth for operative engagement with saidcircumferential grooves.

1. A pump and strainer assembly comprising a stationary pump housinghaving an inner wall defined by a surface of revolution forming a pumpchamber in said housing, one end of said chamber being provided with aninlet, a rotary drive shaft mounted in said chamber concentric with theaxis of said surface of revolution, an impeller secured to said driveshaft, a shell enclosing at least a part of said pump housing, saidshell forming with the wall of said enclosed pump housing a separateoutlet chamber, the portion of said housing enclosed by said shell beingprovided with a plurality of strainer passages, said impeller comprisinga plurality of semielliptical wings, said wings being generally disposedin planes angularly related to each other and angularly related withrespect to the axis of said surface of revolution.
 2. An assembly asclaimed in claim 1 wherein said impeller is folded to form two wings. 3.An assembly as claimed in claim 2 wherein said wings are formed by twoplanes meeting along a straight line.
 4. An assembly as claimed in claim2 wherein said wings are formed by two intersecting generally arcuaTelyformed members.
 5. An assembly as claimed in claim 2 wherein the foldingedge of the impeller is opposite the inlet of the pump chamber.
 6. Anassembly as claimed in claim 2 wherein said wings have differentlengths.
 7. An assembly as claimed in claim 1, wherein at least aportion of said inner wall defining the pump chamber is provided with aseries of circumferential grooves, and the margins of saidsemielliptical wings are provided with teeth for operative engagementwith said circumferential grooves.